6 Ways Alcohol Affects Your Progress
1. Alcohol Puts Fat Burning on Hold
Alcohol turns into acetate in the body, which is a preferential fuel source to fat. Therefore after the consumption of alcohol, for up to 20.5 hours, fat burning is put on hold whilst your body uses up the acetate for energy. As if that wasn't bad enough, there's also a net fat increase during those hours too if the alcohol was consumed in addition to your normal food intake; not great for fat loss! Even more depressing is that it only takes one or two drinks to cause all this to happen.
2. Alcohol Reduces the Muscle Adaptations to Weight Training
Alcohol should not be ingested after resistance/weight training, especially if you're male, as it could potentially hamper the desired muscular adaptations by reducing anabolic signaling/inhibiting muscle protein synthesis and may therefore impair recovery and adaptation to training and/or subsequent performance.
3. Alcohol Reduces Sleep Quality
Just one or two alcoholic drinks are enough to reduce the amount of time you spend in REM (rapid eye movement) sleep[5,6]. REM is thought of as the most important and restorative phase of sleep so cutting this in half is never a good idea.
4. Alcohol Reduces the Energy Recovery Rate in the Muscles
Alcohol slows down glycogen resynthesis by almost 50% over the first 8 hours post workout and still not fully recovering at 24 hours. This means it'll take much longer to recover from your training. This is particularly bad news if you exercise every day or even worse news if you train twice a day.
5. Alcohol Reduces Athletic Performance
The hangover effect from alcohol consumption has been shown to reduce athletic performance by 11.4%. You're also more likely to skip your workout if you're hungover; remember, the only bad workout is the one you didn't do! The more often this happens, the more your gym performance will suffer.
6. Alcohol Increases Injury Risk
Alcohol consumption appears to have a causative effect in sports related injury, with an injury incidence of 54.8% in drinkers compared with 23.5% in nondrinkers. This may be due in part to the hangover effect of alcohol consumption, which has been shown to reduce athletic performance.
It is important that we fully understand the consequences of our actions rather than pretending that a drink or two a week won't hurt because it will to some degree. It's OK to have a drink occasionally, just don't expect to get much in the way of results that week.
 Sonko BJ, Prentice AM, Murgatroyd PR, Goldberg GR, van de Ven ML, Coward WA: Effect of alcohol on postmeal fat storage. Am J Clin Nutr. 1994 Mar;59(3):619-25
 Siler SQ, Neese RA, Hellerstein MK: De novo lipogenesis, lipid kinetics, and whole-body lipid balances in humans after acute alcohol consumption. Am J Clin Nutr. 1999 Nov;70(5):928-36
 Duplanty AA, Budnar RG: Effect of Acute Alcohol Ingestion on Resistance Exercise-Induced mTORC1 Signaling in Human Muscle. J Strength Cond Res. 2017 Jan;31(1):54-61
 Evelyn B. Parr, Donny M. Camera: Alcohol Ingestion Impairs Maximal Post-Exercise Rates of Myofibrillar Protein Synthesis following a Single Bout of Concurrent Training. February 12, 2014
 Ebrahim IO, Shapiro CM, Williams AJ, Fenwick PB: Alcohol and sleep I: effects on normal sleep. Alcohol Clin Exp Res. 2013 Apr;37(4):539-49
 Miyata S, Noda A, Ito N, Atarashi M, Yasuma F, Morita S, Koike Y: REM sleep is impaired by a small amount of alcohol in young women sensitive to alcohol. Intern Med. 2004 Aug;43(8):679-84
 Burke LM, Collier GR: Effect of alcohol intake on muscle glycogen storage after prolonged exercise. J Appl Physiol (1985). 2003 Sep;95(3):983-90
 O'Brien CP, Lyons F: Alcohol and the athlete. Sports Med. 2000 May;29(5):295-300